Sewage disposal system



y 1, 1951 w. RIMANN 2,551,395

SEWAGE DISPOSAL SYSTEM Filed Oct. 3, 1946 4 Sheets-Sheet l INVENTOR%L7'E/ ZMA/V/V. BY Ki ATTORNE y 1, 1951 w. RIMANN 2,551,395

SEWAGE DISPOSAL SYSTEM Filed Oct. 5, 1946 4 Sheets-Sheet 2 INVENTOR WA75 P/M/i/v/v.

Q BY w ATTORN Y y 1, 1951 w. RlMANN 2,551,395

SEWAGE DISPOSAL SYSTEM Filed Oct. 3, 1946 4 Sheets-Sheet 5 INVENTOR I WA75,? F/MA/v/v.

ATTORNE.

y 1, 1951 w. RIMANN 2,551,395

SEWAGE DISPOSAL SYSTEM Filed Oct. 5, 1946 4 Sheets-Sheet 4 Q3 INVENTOR I#414 7-5 P/MA/v/v.

ATTORN Y Patented May 1, 1951 SEWAGE DISPOSAL SYSTEM Walter Ri'mann,Winterthur, Switzerland, assignor'to Sulzer'Freres, Societe Anonyme,Winterthur, Switzerland Application October 3, 1946, Serial No. 701,004In Switzerland June 5, 1946 4 Claims. 1

The invention relates to sewage disposal systems having a disintegratorwith cutting device for reducing the size of the particles of the solidmatter' carried in the sewage and includes means for temporarilyreversing. the operation of the disintegrator to loosen periodically thesubstance adhering to the cutting device and thus prevent thedisintegrator from becoming choked. An object of the invention consistsin the provision of controlling means for the operation of the cuttingdevice, through which atemporary backward motion of the cutting deviceis effected.

The system according to the invention comprises an open containercommunicating with the intake of the disintegrator and receiving lumpy,solid matter and liquid separated from the main stream of sewage. Thedisintegrator discharges into the sewage stream after the point wherethe solid matter and a portion of the liquid has been separated. If thedisintegrator becomes clogged the liquid level in the container rises.The control means for temporarily reversing the operation of thedisintegrator are either automatically operated in dependence on theliquid level in the container or, if manual operation is preferred, areplaced in a position where the oper ator can see the liquid level in thecontainer. Other modifications of the invention include automaticclockwork controlled means for reversing the rotation of the motoroperating the disintegrator atregular, predetermined time intervals andfor regular, predetermined periods, for operating the motor reversingmeans in dependence on the strength of the current flowing through themotor, and for semi-automatic operation of the reversing means wherebyreversing of the motor is actuated by manual operation of a push buttonand is automatically continued for a predetermined period, whereafterthe motor is automatically stopped and restarted to normal operation.

An object of the invention resides in the provision of a cam operatedmain switch of the motor for the disintegrator, whereby the cam isoperated by an auxiliary electric motor and comprises a portion holdingthe main switch in position for normal operation, another portion forpositioning the main switch for reversed operation of the motor, andintermediary portions for positioning the main switch for stopping themotor between normal and reversed operation.

On the drawing examples of arrangements according to the invention areillustrated diagrammati'cally.

Figs. 1 and 2 show a plant for reducing the size of solid mattercontained in town sewage in part sectional elevation and plan view,respectively,

Fig. 3 shows a disintegrator in section, an electric motor therefore,and a wiring diagram for push button control of the plant,

Fig. 4- illustrates a hand operated switch gear with automaticreversing,

Fig .5 illustrates an actuating mechanism for the switch gear inresponse to a certain liquid level,

Fig. 6 shows a switch gear actuated by a time switch, and

Fig. '7 a switch gear actuated, according to the output.

Referring more particularly to Figs. 1 and 2, a channel serves forconducting the sewage from a municipal system of sewers to one or moresettling tanks 2, from which the settled mud is withdrawn under waterand led .to closed fermentation chambers, not shown in the drawing. Thesewage flows along the channel l in the direction of the arrow 3, thelarger particles of solid matter carried in the water being heldback bythe grid 4, so that they can be removed later by the prongs of thecleaning rake 5, and brought through the chute 6 into the channel I.From the channel '5 the solid particles are washed by means of a streamof rinsing water into the shaft or container 8, whose water level 9 iskept below the water level In of the channel I. The flow from thechannel 1 and, if necessary, an additional flow through the pipe 12,controlled by means of the throttle valve H, are maintained in such away that it corresponds to the quantity withdrawn from the shaft 8through the suction pipe I3, with undisturbed working of thedisintegrator.

In the case of simply designed sewage plants which have no fermentingchambers, or even allow the sewage to pass direct into the sea, thesolid matter cut up by the size-reducing device is worked up into manureor allowed to pass away into the sea.

The disintegrator l4, driven by an electric motor I5, delivers thereduced solid substances together with the water through the deliverypipe IE to the basin 2. For the pipes l3 and [6, stop valves I! and [8are provided. The motor I5 is switched on and ofl by means of the mainswitch in the switch box 19 by operating the switch handle 20. In thesame way the push button remote control 21 at the shaft 8, which isconnected to the switch box l9, serves for operating the main switch.

Instead of the channel I, a tipping truck service may be provided, thetipping truck being loaded under the chute 6 with the solid substances,drawn to the shaft 3 and there emptied. Then water is introduced solelythrough the pipe 52 and regulated by means of the throttle valve H.

Ihe disintegrator l4, Fig. 3, with the cutting device, the rotatingknife 23, the grid 2d and the stationary counter-knife 25, is connectedthrough its intake 26 to the shaft 8, Figs. 1 and 2. The solidsubstances carried over in the rinsing water are reduced in size by thecutting device 23, 25, Fig. 3, and pass through the grid 24 into thedelivery branch 21 and in the delivery pipe i 6. The motor it drives therotating knife 23.

With the diiferent character of the substances carried in the water,there occurs not only great wear in the cutting device 2325, but also agradual choking which can be only partly prevented by the counter-knife25,. which keeps the upper side of the knife 23 clean. The choking maytake place more or less quickly, and even quite suddenly. The chokingoccurs by substances sticking between the knives 23 and the grid 24 andbeing carried round with the knives 23, so that disintegration offurther substances is more or less prevented.

As soon as choking of the disintegrator device l4 begins, this makesitself perceptible by a rise in the water level 8 in shaft 8, Figs. 1and 2, and the man in charge, by means of the press button switch 2!,causes the motor i and the cutting device to be reversed for a shorttime. Instead of, as hitherto, having to stop the disintegrator device,open it up and clean it by hand, the following simplified operation hasbeen found much more effective: rotation of the knives 23 is not onlyinterrupted at as regular intervals as possib1e, but also reversed.Thereby any substances stuck between the knives 23 and the grid 24 areloosened very easily and in a very short time. The more often thiscleaning is done, the more effective it is, above all if it is donepromptly when any choking starts. After running backwards for a shorttime, mostly for a few seconds. the device 23--25 becomes clean and canagain be put into normal service.

As seen in Fig. 3 two main switches 28 and 29 are provided, which switchthe motor l5 on to and ofi from the supply lines so and are fitted inthe box I9, Fig. 2. With switch 28 closed, as

28 is actuated by means of the relay 3i and the switch 29 by means ofthe relay 32, these relays closing the switches 28 and 29 against theforce of compressed springs 33, 34 acting on the switchbars. Theswitches 28 and 29 are operated by auxiliary switches 35 and 36 by hand,by means of the push buttons 3?, 38. Further, the switches 35 and 36 arealso provided with self-holding switches 39 and 4!} respectively, andthe switches 4| and 42 serve for stop-ping the motor i5. The switch 4!is actuated by means of the push button 43; the switch 42 is opened bythe excess current bobbin 44 if the current exceeds a maximum.

The method of working is as follows:

With the plant at rest, the switches 28 and 29 are open. By pressing theknob 31 the auxiliary switch 35 closes the contacts 45 so that theelectric wire 41 is connected through contacts 48 and the closed switch4 l, and also through contacts 50 and the switch 36 with the electricwire 5! to the switch 3|, and through its bobbin to t e. wire 4 52 andthrough the switch 42 to the wire 53 and thereby to another phase.

The coil of the relay 3i is thereby energized and closes the switch 28for the motor I5 rotating normally, and at the same time closes also theself-holding switch 39, so that when push button 37 is released, andpressed back to the left by the compressed spring, the switch 35 opensthe contacts 45 and closes the contacts 45, the relay 3! receivescurrent through wire 54 and the closed switch 39 which is thereby heldin closed position.

For changing the direction of rotation of the motor l5, button 38 ispushed. The switch 36 opens the contacts 5!) and thus the wire 54 isdisconnected from the wire dl and the current to the relay 3! isinterrupted, the switches 28 and 39 are opened and the motor I5 iswithout current, so that it comes to a standstill. Only when closing thecontacts 4% in the end position of the switch it, the coil of the relay32 receives current through the wire 55 and closes the main switch 29and the self-holding switch 40. In this way, the relay 32 is connectedthrough the wire 55 to the wire 4! and remains closed when the pressbutton 38 is released. The wire 51 connects the relay 32 through switch42 to wire 53. The motor l5 and the knives 23 then rotate backwards inorder to loosen the substances which have become stuck in the knives.

If the man in charge then actuates the push button 31, the motor andknives are again switched in to rotate in the manner described. Theoperator can stop the disintegrator i l with the help of push button 43,since switch 4| interrupts the current for both relays 3i and 32. Theexcess-current coils open switch 42 if the current to motor 55 exceeds apredetermined maximum. This would occur if the demand for power of thedevice It became too great in consequence oi sudden choking, and themotor would be overloaded. When opening the switch 42, the relays 3i and32 descend and the main switch 28 is opened.

Instead of changing the direction of rotation by hand, a device as shownin Fig. 4 effects this change automatically. The motor I5 is suppliedwith current from the network 3!! and a main switch 5% is provided inthe conduits, which in the two positions I and III interchanges twophases with each other, whilst in the position II the current isinterrupted. The switch 59 is controlled by the cam ti through theroller 68, the cam being driven by the control-motor 62 as soon as theman in charge operates the hand switch 53 and thus closes the electriccircuit through the wire 54, the bobbin of the relay and the wire 66.The relay t5 then connects wire 64 to wire 5'5. Relay 65 remains closedonly as long as the hand switch 63 is closed and turns motor 62 untilconnection is made between conduits 54 and 67 through conduit iii,contact strip 68 and contact member 59.

By rotation of cam (H by motor $2 in the direction of the arrow rollertill leaves track H, comes on to track 52 and turns switch 59 into theposition II. Thus current to motor i5 is cutoff, so that it can come torest. When cam ti is rotated further, the roller Si] is raised on totrack l3 andthe switch 59 comes into position III; In this. Way theconnections of the motor It to the two phases are interchanged and motorit; drives the knife 23 backwards. This continues until the cam track'53 has all rotated under the roller 6d and the latter comes on to trackM; the switch 59 then again stands, in the position 11 and ourrent tothe motor I5 is interrupted for a short time. The roller 60 thendescends on to track TI, and the switch again comes into position I, andthe cutting device 23 is driven in the normal direction of rotation.Since the cam E! has then turned through 360, the fixed contact 69 hasleft the contact strip 53 and motor 62 together with cam 6i come torest. Consequently from that time motor [5 continues to run in thenormal direction of rotation until the hand switch 63 is again operated.

In Fig. 5 the switching-in of the motor 52 is controlled automaticallyin accordance with the liquid level F3, for instance in the shaft 8,Fig. l, which communicates with the intake of the disintegrating device14. If the device becomes choked, and the delivery from it diminishes,the liquid level 9 rises, the float 15 also rises and the rope Tl,loaded with the suspended weight it, operates the swtich lever 79 bymeans of the stop 78. The lever iii is removed from the stop 8| againstthe force of the spring 8i} and pressed on to the contact 82, so thatcoil 83 receives current and closes the relay 65. In this way thecontrol motor 62 is switched on and, in the manner already described,causes the cam 6| to rotate through 360, thus bringing switch 59 fromposition I into positions II and III and back into position I. Continuedrise of the liquid level 9 causes stop 18 to pass lever '19.

By that time, however, the aforedescribed operations are completed andthe cleaned disintegrating device acts again with undimished throughput.The liquid level a in shaft 8 again falls to its proper value, so thatfioat l5 and the stop ":8 descend. In consequence of the yielding of therope H, the stop 18 now slides along the sloping edge 34 of the lever 19into the position shown in the drawing, which is defined by a guide 85for the rope 71.

In the arrangement according to Fig. 6 the motor 62 is actuated independence on a time switch whose disc 86 is driven by a clockwork (notshown) and makes a complete revolution within a certain time, forinstance in 15 minutes. The disc 86 rotates in the direction of thearrow; in one of the holes 8'! a pin 88 is inserted which, in theposition shown in the drawing, keeps the switch 83 closed against theforce of the spring 98. Because of this, the relay 65 closes the circuitand current is supplied to the motor 52. Consequently the cam Bl turnsonce through 360 in the manner described, whereby the motor [5 is causedto run backwards for a short time, whilst it runs in the normaldirection for the rest of the time. As soon as the pin 88 is rotatedpast the cam 9 i, switch 89 is again opened by the spring fill.

If the disc 86 is driven by means of a reduction gear from the shaft ofthe motor 15 instead of from a time switch, the switching takes place independence on a certain number of turns of the cutting knife 23.

In the system shown in Fig. 7 the switching is efiected when the torqueof the motor I5 rises beyond a definite value, since the power requiredby the cutting knife 23 has increased in consequence of the choking. Forthis purpose a power meter 92 is fitted into one phase, its coil 93being excited proportionally with the current passing through that phaseto the motor 15. At a certain value of this excitation, which may bealtered by means of the adjusting resistance 94, the coil 83 of therelay 55 is so strongly excited that the relay 65 closes, motor 62receives current and the cam BI is rotated. When the motor 15 is 6switched off by switch 59, the coil 93 is without current and the relay55 opens. Meanwhile however, the contact member 69 has been connected towire 54 through the strip 63.

The invention is not confined only to municipal or other waste water orsewage plants, but may be adopted wherever the substances carried overin a liquid must for any reason be reduced in size.

I claim:

1. A control system for the electric motor driving a sewagedisintegrator, said system comprising an electric wiring systemincluding a main switch having three operating positions: one in whichthe motor is rotated in normal operating direction, one in which nocurrent is supplied to the motor, and one in which the motor is rotatedoppositely to normal operating direction, a mechanism connected to andactuating said main switch, an auxiliary motor operating said mechanism,electric wiring connected with said auxiliary motor and including amomentary switch for starting said auxiliary motor and a rotatingcontact switch connected to and operated by said auxiliary motor andcontinuing supply of current to said auxiliary motor when said momentaryswitch is reopened, said rotating switch comprising disconnecting meansfor interrupting current supply to said auxiliary motor when said mainswitch is in normal main motor operating position said mechanismcomprising a cam roller connected with said main switch, and a cammember engaging said roller and being connected to and rotated. by saidauxiliary motor, the rotatin part of said contact switch being mountedon said ca-m member.

2. A control system as defined in claim 1, said cam member comprising acam portion for holding said roller and main switch in position fornormal operation of said main motor, and comprising another cam portiondisposed substantially diametrically opposite said first cam portion forholding said roller and main switch in position for reverse operation ofsaid motor.

3. A control system as defined in claim 2, said cam member comprisingtwo additional cam portions interposed between said first and said othercam portion for holding said roller and main switch in position where nocurrent is supplied to the motor of said disintegrator.

4. A control system for the electric motor driving a sewagedisintegrator, said system comprising an electric wiring systemincluding a main switch having three operating positions: one in whichthe motor is rotated in normal operating direction, one in which nocurrent is supplied to the motor, and one in which the motor is rotatedoppositely to normal operating direction, a mechanism connected to andactuating said main switch, an auxiliary motor operatin said mechanism,electric wiring connected with said auxiliary motor and including amomentary switch for starting said auxiliary motor and a rotatingcontact switch connected to and operated by said auxiliary motor andcontinuing supply of current to said auxiliary motor when said momentaryswitch is re-opened, said mechanism comprising a cam roller connectedwith said main switch, and a cam member engaging said roller and beingconnected to and rotated by said auxiliary motor and comprising a camportion for holding said roller and main switch in position for normaloperation of said main motor, said rotating switch comprisingdisconnecting means so connected with said cam member as to inter-REFERENCES CITED The following references are of record in the file ofthis patent;

UNITED STATES PATENTS Number Name Date Given Nov. 8, 1927 Nogosek July25, 1933 Alexay Apr. 25, 1939 Lum Feb. 18, 1941 Brentz Jan. 20, 1942Durdin Sept. 8, 1942 Blodgett Mar. 14, 1944-.

